Remote-controlled, work-capable miniature vehicle

ABSTRACT

A work-capable, miniature vehicle includes a small-scale hydraulic system, a propulsion system, and a means for remote control. The propulsion system includes a plurality of metal tracks, which are individually controlled. The vehicle is adaptable for performing work in hazardous areas. The vehicle comprises a completed vehicle and a kit including the vehicle components.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of and priority to PCTApplication Serial No. PCT/US01/, for inventor Andrew W. Gordon, filedby DirtBilt, Inc., on Oct. 26, 2001, which is incorporated by referenceherein in its entirety.

NOTICE OF COPYRIGHT PROTECTION

[0002] A portion of the disclosure of this patent document and itsfigures contain material subject to copyright protection. The copyrightowner has no objection to the facsimile reproduction by anyone of thepatent document or the patent disclosure, but otherwise reserves allcopyrights whatsoever.

FIELD OF THE INVENTION

[0003] The present invention relates in general to small-scale vehiclesand in particular to remote-controlled, small-scale vehicles.

BACKGROUND

[0004] A variety of small, remote-controlled vehicles are available onthe market. These vehicles are commonly radio-controlled “toy” vehicles,such as cars or trucks, which are built primarily for entertainmentpurposes. Such toy vehicles are not made to accomplish work and,therefore, do not include robust propulsion and accessory systems. Incontrast, full-size machines designed to perform work have very robustpropulsion and accessory systems.

[0005] For example, a small, tracked vehicle conventionally includes asmall battery-powered motor driving a plastic or rubber track or mayeven include a hidden drive wheel, relegating the track to meredecoration. As a result, a small, tracked vehicle may be able to pushonly very small items, weighing much less than the vehicle itself. Also,the small vehicle may be able to traverse only minimal obstacles and mayoperate for a short period of time before requiring its batteries to becharged or replaced. Many conventional toy vehicles are powered bylimited-life power sources. For example, a toy vehicle utilizing anickel-cadmium power supply may have an elapsed running time of only tento fifteen minutes.

[0006] In contrast, a larger tracked vehicle includes a powerfulelectric or combustion engine driving a metal track. A larger vehicle iscapable of pushing very heavy objects and traversing substantialbarriers. With large fuel tanks and/or battery packs, a larger vehicleis able to perform work for an extended period of time.

[0007] Accessory systems on small vehicles are designed primarily forform rather than function. For example, on a conventional toy bulldozer,the blade assembly is raised and lowered using a servo, battery-poweredmotor, and/or spring-driven mechanism. In contrast, a large, scale-sizebulldozer utilizes a hydraulic system to raise and lower the blade.

[0008] Conventional small, remote-controlled vehicles appeal toindividuals purchasing a model for entertainment. However, serious modelenthusiasts, organizations wishing to use remote-controlled vehicles inhazardous situations, and others desire small-scale vehicles having morerobust features and capabilities than conventional toy vehicles. Thus itwould be advantageous to provide a small-scale, remote-controlledvehicle that is capable of performing work.

SUMMARY

[0009] Embodiments of the present invention provide miniature vehiclescapable of performing work. One such embodiment of the present inventioncomprises a miniature vehicle that is a small-scale version of afull-size machine and that is remote-controlled. The miniature vehicleincludes a working hydraulic system for manipulating attachments and apropulsion system having individually controllable metal tracks. Theminiature vehicle is capable of performing work for recreationalpurposes, and commercial and law enforcement-related purposes, such asthe work involved in dealing with hazardous materials or surveillance.

[0010] In embodiments of the present invention, a miniature vehiclecomprises a frame, on which a propulsion system and a hydraulic systemare mounted. The miniature vehicle comprises a first actuator to controlthe propulsion system and a second actuator to control the hydraulicsystem. The propulsion system may include a plurality of metal tracks,wherein each track comprises a plurality of metal links attachedpivotally to the two adjacent links to form a continuous loop. Thepropulsion system includes a discrete control mechanism for each track.For example, in an embodiment of the present invention, a miniaturebulldozer includes a separate control mechanism for each track so thatturning the bulldozer is accomplished by varying the speed and/ordirection of the individual tracks. The propulsion system includes apower source, such as a battery. In an embodiment of the presentinvention, a gel-cell, twelve-volt battery provides the vehicle with theadvantage of a relatively long operating time. The propulsion systemalso includes an electronic speed control linked to a radio-control orother control system.

[0011] A hydraulic system in an embodiment of the present invention issimilar to a brake system in an automobile, comprising a master cylinderin fluid communication with at least one slave cylinder and forming aclosed loop system. The hydraulic system includes a rack-and-pinionmechanism, which is attached to an input shaft of the master cylinder.Rotation of the pinion gear causes the rack to move and causes inwardmovement of the input shaft in the master cylinder. This inward movementforces hydraulic fluid through hydraulic lines to a slave cylinder. Thehydraulic pressure caused by the fluid movement causes extension of anoutput shaft of the slave cylinder.

[0012] The pinion gear is rotated by an electric motor, which isconnected to and activated by a toggle switch. The toggle switch is, inturn, activated by a radio-controlled servo. In embodiments of thepresent invention, a hydraulic system can utilize mineral oil as thehydraulic fluid. Mineral oil provides the advantages of being non-toxicand non-staining.

[0013] Embodiments of the present invention include a body, or shell,for a miniature vehicle. A body attaches to the frame and may beinterchangeable with other bodies. For example, a bulldozer body can beinterchanged with a tank body. Examples of bodies in other embodimentsinclude a truck body or a crane body.

[0014] In an embodiment of the present invention, a miniature bulldozerincludes a bulldozer blade. The bulldozer blade is connected to thehydraulic system so that the hydraulic system raises and lowers theblade. The bulldozer may also include a ripper arm. The ripper arm isalso attached to the hydraulic system so that it may be raised andlowered.

[0015] Embodiments of the present invention include a wireless videocamera, sensor, detector and/or sampling devices mounted directly orindirectly to the vehicle frame. Embodiments for use in a lawenforcement or military capacity include weapons and detectors, such asland mine detection and/or pre-detonation devices.

[0016] An embodiment of the present invention provides advantages overconventional small, remote-controlled toy vehicles. These advantagesinclude robust propulsion and hydraulic systems in a miniature,remote-controlled, scale-size vehicle. Such features provide advantagesto the serious hobbyist, to organizations wishing to useremote-controlled vehicles in hazardous situations, and others.

[0017] One advantage of the present invention is that the robustpropulsion system resembles that of a full-size machine and allows thevehicle to traverse terrain and obstacles beyond the capabilities of aless robust, remote-control vehicle. Another advantage is that a workinghydraulic system closely reflects such a system in a full-size machineand allows the small vehicle to perform tasks that a toy vehicle cannot.

[0018] Embodiments of the present invention have the further advantageof reducing the safety risks encountered by police officers and militarypersonnel in hazardous situations. For example, an embodiment includinga video camera performs reconnaissance in a hazardous situation thatwould otherwise require the presence of a person.

[0019] Further details and advantages of the present invention are setforth below.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] These and other features, aspects, and advantages of the presentinvention are better understood when the following Detailed Descriptionis read with reference to the accompanying drawings, wherein:

[0021]FIG. 1 is a side perspective view of an embodiment of the presentinvention as a bulldozer.

[0022]FIG. 2 is a side, rear view of the drive components in anembodiment of the present invention.

[0023]FIGS. 3A, 3B, 3C, and 3D illustrate components of a trackpropulsion system in an embodiment of the present invention.

[0024]FIG. 4 is a top perspective view of a hydraulic system in anembodiment of the present invention.

[0025]FIGS. 5A and 5B illustrate a ripper assembly in an embodiment ofthe present invention.

[0026]FIGS. 6A and 6B illustrate various shells for attachment to aframe in an embodiment of the present invention.

DETAILED DESCRIPTION

[0027] Embodiments of the present invention include a frame on which ismounted a propulsion system, including metal tracks, a hydraulic system,a power supply, and a control system. These aspects provide robustnessto a miniature vehicle, allowing the vehicle to perform work. In anembodiment of the present invention, the control system is aremote-control system, such as a radio-control system, which provides anoperator of the miniature vehicle the ability to operate the vehicle inremote locations.

[0028] FIGS. 1-6 illustrate various aspects of embodiments of thepresent invention as a small-scale version of a full-size vehicle, whichis capable of performing work. FIG. 1 illustrates an embodiment of thepresent invention as a miniature bulldozer 120. Embodiments of thepresent invention comprise a frame to which other components may bemounted. The frame (not shown) comprises aluminum and/or some othermaterial suitable for mounting various components of the machine.

[0029] A propulsion system is mounted on the frame of miniaturebulldozer 120. The propulsion system comprises a pair of metal tracks105 a and 105 b. A gear 107 a drives track 105 a. A series of rollers109 a-d guide the bottom portion of track 105 a. The propulsion systemfurther comprises a guide wheel 108 on which track 105 a is seated.

[0030] Bulldozer 120 includes an actuator (not shown) for activating andcontrolling the propulsion system. For example, the propulsion systemactuator on bulldozer 120 may include a remote-controlled electronicspeed control. Alternatively, the actuator includes a pre-programmed,computer-controlled propulsion system actuator. The actuator controlstracks 105 a and 105 b individually, allowing the bulldozer 120 toexecute turns by varying the speed and/or direction of tracks 105 a and105 b.

[0031] Referring again to FIG. 1, bulldozer 120 also comprises abulldozer blade assembly 110, 111 and a ripper assembly 112, 113. Blade110 is rigidly connected to a blade arm 111, which is pivotallyconnected to the frame of bulldozer 120. Ripper 112 is similarlyattached to the frame of bulldozer 120 via a parallelogram ripper arm113. Both the blade 110 and the ripper 112 are operated with a hydraulicsystem mounted on or to the frame.

[0032] In the embodiment illustrated in FIG. 1, a hydraulic systemincludes hydraulic slave cylinders 101 a, 101 b, and 103. Slavecylinders 101 a and 101 b are in fluid communication with a first mastercylinder (not shown). Slave cylinder 103 is in fluid communication witha second master cylinder (not shown). Slave cylinders 101 a and 101 bare further attached to blade arm 111 and operate to raise and lowerblade 110. Slave cylinder 103 is attached to ripper arm 113 and operatesto raise and lower ripper arm 113 and ripper 112.

[0033] In addition to a propulsion system actuator, bulldozer 120 alsoincludes an actuator to separately control the hydraulic systemsattached to blade 110 and ripper 112, respectively. Similar to thepropulsion system actuator, the hydraulic system actuator may include aremote-controlled system, such as a radio-controlled servo system.

[0034] The bulldozer 120 in FIG. 1 is robust and capable of performingwork. For example, in experimentation, bulldozer 120 was found to becapable of pushing a cinder block, weighing over thirty-six pounds.Also, bulldozer 120 was found to be capable of pulling a wagon carryingin excess of fifty-five pounds.

[0035] Propulsion System

[0036] As described briefly above, an embodiment of the presentinvention comprises a propulsion system. The propulsion system includeswheels and/or tracks. FIG. 2 illustrates a track propulsion system in anembodiment of the present invention.

[0037] The track propulsion system shown in FIG. 2 comprises a pair oftracks 105 a and 105 b. Each of the tracks 105 a, 105 b is driven by adiscrete control mechanism. Gears 107 a and 107 b drive tracks 105 a and105 b, respectively, and are connected to matching drive systems. Gear107 a is attached coaxially to drive shaft 208. In the embodiment shownin FIG. 2., gear 107 a is attached at an outside end of drive shaft 208.In other embodiments, the drive gear 107 a is attached at variouspositions along the length of drive shaft 208. Gear 202 is also attachedcoaxially to drive shaft 208 so that when gear 202 rotates, drive shaft208 rotates as well. Rotation of drive shaft 208 causes rotation of gear107 a and a corresponding movement of track 105 a. Gears 107 a and 202may be of the same or different sizes.

[0038] Gear 202 is engaged with gear 203. Gear 203 is coaxially attachedto an output shaft (not shown) from motor 201 a. The embodiment shown inFIG. 2 comprises a motor 201 a. Motor 201 a drives a single track.Various other embodiments of the present invention comprise a more thanone motor, depending on the wheel/track design and degree of controldesired. Motor 201 a provides sufficient power to perform work. In oneembodiment of the present invention, the motor, such as motor 201 a inFIG. 2, is a twelve-volt motor, which provides an amount of torquesufficient to allow the machine to push or pull heavy loads.

[0039] The machine shown in FIG. 2 also includes a speed control 205.The speed control 205 is attached to the motors 201 a, b by electricalcontrol wires 204 a, b, respectively. Speed control 205 may comprise anelectronic speed control, providing proportional and infinitely variableindividual speed and directional control of motors 201 a, b. Forexample, an embodiment of the present invention utilizes the Novak SuperRooster reversible digital speed control to distribute power to themotors.

[0040] The speed control is attached to various other components. Forexample, in an embodiment of the present invention, comprising aradio-controlled machine, the speed control is attached to a radioreceiver. Attached to the radio receiver is an antenna that receivessignals from a transmitter. The transmitter includes a right and a leftjoystick. When the right joystick is moved vertically forward orbackward from a neutral and/or centered position, the joystick movementcauses a corresponding movement in the right track of the machine. Ifboth joysticks are moved forward or backward in unison, the machinemoves forward or backward respectively. If the left and right joystickare moved in different directions or in differing amounts, the machineturns towards the track which is moving more slowly. For example, if theright joystick is pulled backward, causing the right track to reverse,and the left joystick is pushed forward, causing the left track to moveforward, the machine turns to the right.

[0041] In other embodiments of the present invention, the speed controlincludes mechanical controls, such as toggle switches. The toggleswitches are connected to miniature control devices in the machine thatare visible to a person observing the machine working. The movement ofthe control devices provides animation in an embodiment of the presentinvention.

[0042] In the embodiment shown in FIG. 2, gel-cell battery 207 is apower source that provides energy to the speed control 205 and motors201 a, b. The battery 207 is electrically connected to speed control 205via a wire 206. In the machine shown in FIG. 2, a 12-volt gel cellbattery has an operating time of approximately 2 to 6 hours betweencharges, depending on operating conditions and loads.

[0043] The track 105 a shown in FIG. 2 comprises a plurality of metallinks. FIGS. 3A-D illustrate an embodiment of elements of track 105 a inseparate views, the combination of elements of track 105 a, and theinteraction of elements of track 105 a with drive and suspension systemsof the present invention.

[0044]FIG. 3A is a side view of a track link 301 a. Track link 301 acomprises a pair of connectors, represented by connector 302 a in FIG.3A. As shown in FIG. 3C, the connectors 302 a, b are mountedtransversely to track link 301 a and project beyond the surface of tracklink 301 a.

[0045]FIG. 3C provides a perspective view of the link from above asurface of link 301 a to which the connectors 302 a, b are attached.Connector 302 a is parallel to connector 302 b and each is shaped sothat the space between them is narrow at one end and wide at the otherend. The narrow and wide ends of connectors 302 a, b are complementary.The distance between the outside edges of the connectors 302 a, b at thenarrow end is less than the distance between the inside edges of eachconnector at the wide end, such that the narrow end may be inserted intothe wide end of an adjacent link. The adjacent links are attached byvarious pivotal means, such as pins and rods.

[0046]FIG. 3D illustrates track 105 a, comprising a plurality of links301 a-d so attached. As shown in FIG. 3D, once the links 301 a-d havebeen pivotally attached, they functionally engage drive gear 107 a. Oncethe links 301 a-d are engaged with gear 107 a, then when gear 107 arotates, track 105 a moves, sliding along roller 109 a with which track105 a is also engaged.

[0047] The tracks illustrated in FIGS. 3A-D may comprise variousmaterials, including rubber, plastic, and/or metal. In a preferredembodiment of the present invention, the tracks are metal, and the metalis of sufficient hardness so as to resist galling. For example, thetracks may comprise stainless steel and/or other steel and steelcomposites. Alternatively, the links may comprise a relatively hard orzinc-anodized aluminum.

[0048] In an embodiment of the present invention as a front-end loader,the propulsion system comprises four wheels. Power is supplied to one ormore of the four wheels by an electric motor, such as the motors shownin FIG. 2. Steering of a front-end loader is accomplished through use ofdifferential speed to wheels on opposite sides of the machine and/or bythe addition of a steering mechanism to the front or rear of themachine.

[0049] In an embodiment of the present invention as a tank, suspensionelements are included in track 105 a for greater realism andfunctionality.

[0050] Hydraulic System

[0051] An embodiment of the present invention comprises a hydraulicsystem for performing work. FIG. 4 illustrates the various components ofa hydraulic system in an embodiment of the present invention. Thehydraulic system shown in FIG. 4 operates the bulldozer blade 110, asshown in FIG. 1.

[0052] The hydraulic system shown in FIG. 4 is similar to a brakingsystem in an automobile and comprises a master cylinder 409 as well as aslave cylinder 101 a. Such a system is known as a closed-loop system. Inthis closed-loop system, a constant volume of fluid is transferred backand forth between the master cylinder 409 and the slave cylinder 101 aduring operation of the hydraulic system. Mineral oil, which isnon-toxic and non-staining, is advantageously utilized as hydraulicfluid in embodiments of the present invention.

[0053] Master cylinder 409 includes an input shaft 408. Movement ofinput shaft 408 causes a corresponding movement of a piston withinmaster cylinder 409. Movement of the piston causes hydraulic fluid to bepressurized within master cylinder 409 on the side towards which thepiston is moving. Master cylinder 409 is in fluid communication withslave cylinder 101 a. When the input shaft 408 is moved inwardly in themaster cylinder, fluid is forced out of the opposite end of mastercylinder 409 through a valve or fitting 410 a into hydraulic line 412 a.

[0054] Slave cylinder 101 a includes a fitting 410 b at one end, whichis attached to hydraulic line 412 a at an end opposite the mastercylinder 409. The pressure of the fluid exiting master cylinder 409causes the fluid to flow through hydraulic line 412 a and enter slavecylinder 101 a through fitting 410 b. This movement of hydraulic fluidinto slave cylinder 101 a causes a piston (not shown) inside slavecylinder 101 a to move in the direction opposite fitting 410 b. Attachedto the slave cylinder piston is an output shaft 411. Movement of thepiston causes a corresponding movement of output shaft 411. Thus, whenhydraulic fluid enters slave cylinder 101 a at one end of slave cylinder101 a, output shaft 411 moves outwardly from the opposite end of slavecylinder 101 a. Movement of the slave cylinder piston forces hydraulicfluid to exit slave cylinder 101 a at fitting 410 d and enter hydraulicline 412 b. The fluid then flows through hydraulic line 412 b and entersmaster cylinder 409 at fitting 410 c.

[0055] Therefore, a control force exerted on input shaft 408 causes acorresponding, opposite movement of output shaft 411. An inward movementof input shaft 408 causes a corresponding outward movement of outputshaft 411. Likewise, outward movement of input shaft 408 causes inwardmovement of output shaft 411.

[0056] The output shaft 411 is functionally connected to a bulldozerblade assembly, including blade 110 and blade arm 111. Output shaft 411is attached to blade arm 111, which is attached to the vehicle frame.Blade arm 111 is also attached to blade 110. In the embodiment shown inFIG. 4, an outward movement of output shaft 411 causes blade 110 tolower. An inward movement of output shaft 411 causes blade 110 to rise.It is known that hydraulic fluid does not compress. Therefore, once theblade 110 is lowered, the blade 110 will not rise unless a force isapplied to the blade 110 and/or output shaft 411 that is greater thaneither the force that the weight of the miniature bulldozer is applyingdownward on the blade 110 or the amount of force the hydraulic system iscapable of withstanding before failure.

[0057] For example, in the embodiment shown in FIG. 4, the hydrauliclines 412 a, b and the fittings 410 a-d on the master cylinder 409 andslave cylinder 101 a are capable of providing hydraulic pressure inexcess of 150 pounds per square inch (PSI). The force the machine iscapable of exerting through the hydraulic system is calculated using theformula, Force=(1/(r_(piston) ²*Π))*Machine Weight, where r_(piston) isthe radius of the piston in inches and Machine Weight is the weight ofthe machine in pounds. In the embodiment shown in FIG. 4, the radius ofthe piston is 0.3125 inches and the machine weights 39 pounds. Applyingthis formula to the embodiment shown in FIG. 4 ((1/(0.3125*3.1417)*39pounds) shows that the machine is capable of exerting a force ofapproximately 127 PSI.

[0058] In the embodiment shown in FIG. 4, the input shaft 408 of mastercylinder 409 is moved using a rack and pinion system. An end of rack 404is attached to input shaft 408. Along one side of rack 404 are teeth.The teeth in rack 404 are transversely engaged with gear 402. To ensurethat rack 404 remains engaged with gear 402, rack 404 rolls along roller401 on the side of rack 404 opposite gear 402.

[0059] The gear 402 is coaxially attached to an output shaft of anelectric motor (not shown). When the electric motor operates, it rotatesgear 402. The electric motor is electrically connected to a switch 407.The switch 407 is connected to and controlled by a servo 406. Battery207 is connected to and provides power for both servo 406 and, viaswitch 407, the electric motor that operates pinion gear 402. A limiter403 is connected to the electric motor to stop the motor when inputshaft 411 reaches its limit of inward or outward movement from mastercylinder 409.

[0060] Embodiments of the present invention further comprise a radioreceiver connected to the hydraulic system for remote operation of thehydraulic system. In various embodiments, the hydraulic system powersvarious types of accessories, such as ripper arm 112 shown in FIG. 1.Examples of these accessories include a gun in the turret of a tank, abucket on a front-end loader, or forks on a fork lift.

[0061] An embodiment of the present invention comprising a miniaturebulldozer further includes a ripper 112. FIGS. 5A and 5b illustrate theripper 112 shown in FIG. 1. The ripper 112 shown in FIG. 5A is anexample of a multi-shank ripper, comprising dual shanks. The ripper 112is attached a to an end of the outer member 501 of parallelogram ripperarm 113.

[0062] In FIG. 5B ripper arm 113 comprises four members, which areattached to form a parallelogram arm. Members opposite one anotherremain in parallel throughout the arm's motion. Multi-shank ripper 112is rigidly attached to member 501. Member 502 is attached to the frameof the machine and remains in parallel with member 501. Members 503 and504 form the top and bottom of the ripper arm and are attached to member502 at one end and member 501 at the other. Members 503 and 504 may beseparated to provide stability to the arm. In an embodiment of thepresent invention, members 503 and 504 are duplicated on an oppositeside of members 501 and 502 to provide further stability. Ripper 112and/or ripper arm 113 is attached to the hydraulic system to facilitateraising and lowering of the ripper 112.

[0063] In embodiments of the present invention, the miniature vehicleincludes interchangeable shells or bodies. FIG. 6A illustrates anembodiment of the present invention as a bulldozer. To attach bulldozerbody 610 to the frame of the vehicle, predrilled holes 601 and 603 inbulldozer body 114 are aligned with holes 602 and 604 in the frame.Fasteners, such as allen-head screws, are then inserted through theholes to attach the body 610 to the frame.

[0064]FIG. 6B illustrates a tank body 605. Tank body 605 comprises twoholes 606 and 607 that align with holes 602 and 604 respectively. Assuch, one body can be easily removed from the frame and a different bodyattached in its place. Other embodiments include bodies of, for example,a crane, a truck, a forklift, a front-end loader, and an armoredpersonnel carrier.

[0065] Embodiments of the present invention include elements that addaspects of a life-size vehicle to a miniature, scale-size vehicle andprovide useful functions for work activities. For example, an embodimentmay include a sound module and lighting accessories. These featuresallow a miniature vehicle to light a work area and to communicate with adangerous person in a hazardous environment.

[0066] An embodiment of the present invention includes a miniaturewireless video camera mounted on the frame. A video camera provides aperson operating the vehicle with a view that approximates the view anoperator of a full-scale vehicle has. A camera provides the personoperating the vehicle in a hazardous situation with a means of viewingsituations encountered by the machine without subjecting the personoperating the machine to the hazard.

[0067] An embodiment of the present invention further comprises weapons,detectors, sensors, and sample gathering devices, which enhance the workcapabilities of the vehicle in hazardous situations. For example, anembodiment comprises a device to deliver tear gas and/or an infraredsensor capable of helping police assess and intervene in a potentiallydangerous situation. Additionally, a vehicle designed to perform landmine detection and removal comprises land mine detectors and/orpre-detonation devices.

[0068] An embodiment of the present invention comprises a kit. In oneembodiment, the kit includes all of the materials necessary to assemblea complete vehicle, such as a bulldozer. In another embodiment, the kitincludes a single sub-system of a vehicle. For example, one kit includesa frame and a propulsion system. A second kit includes a singlehydraulic system. In order to assemble a complete bulldozer, including abulldozer blade 110 and ripper 112, one frame and propulsion kit and twohydraulic system kits are used.

[0069] Other kits according to the present invention include aradio-control system. In an embodiment of the present invention as abulldozer, the kit includes a four-channel radio. The kit also includesa electronic speed control to control each of the two electricpropulsion motors 201 a, b and two servos to control each of the twohydraulic systems for the bulldozer blade 110 and ripper arm 112. Insuch an embodiment, forward and backward movements of a control stick onthe transmitter control the speed and direction of movement of thecorresponding track. Left and right movements of a control stick causeoperation of a hydraulic system.

[0070] The foregoing description of the preferred embodiments of theinvention has been presented only for the purpose of illustration anddescription and is not intended to be exhaustive or to limit theinvention to the precise forms disclosed. Numerous modifications andadaptations thereof will be apparent to those skilled in the art withoutdeparting from the spirit and scope of the present invention.

What is claimed is:
 1. A miniature vehicle comprising: a frame; apropulsion system mounted on said frame; a hydraulic system mounted onsaid frame; a first actuator functionally connected to said propulsionsystem; and a second actuator functionally connected to said hydraulicsystem.
 2. The miniature vehicle of claim 1, wherein said propulsionsystem and said hydraulic system operate to perform work.
 3. Theminiature vehicle of claim 1, further comprising a remote-control systemfunctionally attached to said first actuator and said second actuator.4. The miniature vehicle of claim 3, wherein said remote-control systemcomprises a radio-control system
 5. The miniature vehicle of claim 1,wherein said miniature vehicle comprises a scale-size version of afull-size vehicle.
 6. The miniature vehicle of claim 1, wherein saidpropulsion system comprises a plurality of metal tracks.
 7. Theminiature vehicle of 6, wherein said propulsion system further comprisesa discrete control mechanism for each of said plurality of metal tracks.8. The miniature vehicle of claim 6, wherein said propulsion systemfurther comprises: a power source; a motor functionally connected tosaid power source, wherein said motor comprises an output shaft; a firstgear coaxially attached to said output shaft; a second gear engaged withsaid first gear; a drive shaft coaxially attached to said second gear;and a third gear coaxially attached to said drive shaft, wherein atleast one of said plurality of metal tracks engaged with said thirdgear.
 9. The miniature vehicle of claim 8, wherein said power sourcecomprises a gel-cell battery.
 10. The miniature vehicle of claim 8,wherein said motor comprises an electric motor.
 11. The miniaturevehicle of claim 8, wherein said propulsion system further comprises aplurality of rollers attached to said frame and engaged with each ofsaid plurality of metal tracks.
 12. The miniature vehicle of claim 6,wherein each of said plurality of metal tracks further comprises aplurality of metal links, each of said plurality of metal links havingan inner surface, wherein a pair of spaced apart connectors project fromthe inner surface, and wherein the pair of spaced apart connectors ofeach of said plurality of metal links is pivotally attached to the pairof spaced apart connectors of an adjacent metal link so as to form acontinuous loop.
 13. The miniature vehicle of claim 1, furthercomprising a body mounted on said frame.
 14. The miniature vehicle ofclaim 13, wherein said body comprises a bulldozer body.
 15. Theminiature vehicle of claim 13, wherein said body comprises a truck body.16. The miniature vehicle of claim 13, wherein said body comprises acrane body.
 17. The miniature vehicle of claim 13, wherein said bodycomprises a tank body.
 18. The miniature vehicle of claim 1, furthercomprising a video camera mounted on said frame.
 19. The miniaturevehicle of claim 1, further comprising a sensor mounted on said frame.20. The miniature vehicle of claim 1, further comprising a samplegatherer mounted on said frame.
 21. The miniature vehicle of claim 1,wherein said hydraulic system comprises: a master cylinder having aninput shaft; a slave cylinder having an output shaft; and a hydraulicline in fluid communication between said master cylinder and said slavecylinder.
 22. The miniature vehicle of claim 1, wherein said firstactuator comprises: a power source; and an electronic speed controlelectrically connected to said power source.
 23. The miniature vehicleof claim 1, wherein said second actuator comprises: a power source; amotor operably connected to said power source; an output shaft extendingfrom said motor; a pinion gear coaxially attached to said output shaft;and a rack transversely engaged with said pinion gear and rigidlyattached to said hydraulic system.
 24. The miniature vehicle of claim23, further comprising: a switch functionally connected between saidpower source and said motor; and a servo functionally attached to saidswitch.
 25. The miniature vehicle of claim 24, further comprising aremote-control system functionally attached to said servo.
 26. Theminiature vehicle of claim 1, further comprising a bulldozer bladeassembly mounted functionally on said frame.
 27. The miniature vehicleof claim 26, wherein said bulldozer blade assembly comprises a bulldozerblade and a bulldozer blade arm, wherein said bulldozer blade arm ispivotally connected to said frame, functionally connected to saidhydraulic system, and rigidly connected to said bulldozer blade.
 28. Theminiature vehicle of claim 1, further comprising a ripper assembly. 29.The miniature vehicle of claim 28, wherein said ripper assemblycomprises: a parallelogram ripper arm having a first member, a secondmember, a third member, and a fourth member, wherein said first memberis pivotally attached to a first end of said third member and pivotallyattached to a first end of said fourth member, said second member ispivotally attached to a second end of said third member and pivotallyattached to a second end of said fourth member, and said first member isrigidly attached to said frame; and a multi-shank ripper rigidlyconnected to said second member and functionally connected to saidhydraulic system.
 30. A miniature vehicle comprising: a frame; apropulsion system mounted on said frame; a hydraulic system mounted onsaid frame; a first actuator functionally connected to said propulsionsystem; a second actuator functionally connected to said hydraulicsystem; and a remote-control system functionally attached to said firstactuator and said second actuator; wherein the miniature vehicle furthercomprises a scale-size version of a full-size vehicle, wherein saidpropulsion system further comprises a plurality of metal tracks, each ofsaid plurality of metal tracks having a discrete control mechanism, andwherein said propulsion system and said hydraulic system are operable toperform work.
 31. A hydraulic system for a miniature vehicle comprising:a master cylinder having an input shaft; a slave cylinder having anoutput shaft; and a hydraulic line in fluid communication between saidmaster cylinder and said slave cylinder.
 32. The hydraulic system ofclaim 31, further comprising an actuator attached to said input shaft.33. The hydraulic system of claim 32, wherein said actuator comprises: apower source; a motor operably connected to said power source; an outputshaft extending from said motor; a pinion gear coaxially attached tosaid output shaft; and a rack transversely engaged with said pinion gearand rigidly attached to said input shaft.
 34. The hydraulic system ofclaim 33, further comprising: a switch functionally connected betweensaid power source and said motor; and a servo functionally attached tosaid switch.
 35. The hydraulic system of claim 34, further comprising aremote-control system functionally attached to said servo.
 36. Thehydraulic system of claim 35, wherein said remote-control systemcomprises a radio-control system.
 37. The hydraulic system of claim 33,further comprising a bulldozer blade assembly functionally connected tosaid output shaft.
 38. The hydraulic system of claim 33, furthercomprising a ripper assembly to said output shaft.
 39. A metal track fora miniature vehicle comprising a plurality of metal links pivotallyattached to one another so as to form a continuous loop.
 40. Theminiature vehicle of claim 39, wherein each of said plurality of metaltracks further comprises a plurality of metal links, each of saidplurality of metal links having an inner surface, wherein a pair ofspaced apart connectors project from the inner surface, and wherein thepair of spaced apart connectors of each of said plurality of metal linksis pivotally attached to the pair of spaced apart connectors of anadjacent metal link so as to form a continuous loop.